When it comes to the student debt crisis, Democrats may be undecided on the best approach to tackling it, but presumptive Republican nominee Donald Trump is a big part of the problem, Sen. Elizabeth Warren said in an interview on Tuesday.

When asked whether she preferred Hillary Clinton's plan for debt-free college or Sen. Bernie Sanders' proposal for free tuition at public colleges, the Massachusetts senator refrained from backing either, and instead pointed to the contrast between the Democrats' vibrant debate on how to reduce the nation's $1.2 trillion student loan debt and the GOP's largely nonexistent one.

"Listen to the debate on the Democratic side — we're talking about, 'Should it be free college or debt-free college?'" Warren said. "That's where we're going back and forth and trying to have a conversation— how are we going to pay for it, how do the pieces work to make that happen?"

"Can we just draw the distinction about what it looks like on the other side of the Grand Canyon, where the Republicans are not talking about how to reduce the cost?" Warren continued. "We've got a guy right now who's the nominee who runs [Trump University], which — at least if you read the lawsuits against it — was just out there to try to rip off students. We've got a Republican Party that consistently blocked refinancing any of the student loan debt. This is the big difference."

Warren brought up presumptive Trump's defunct for-profit enterprise Trump University repeatedly during the interview. The venture is currently the subject of a lawsuit alleging that Trump defrauded thousands of students.

The Democratic debate: Last year, Sanders introduced legislation that would make four-year public universities and colleges tuition-free, financed chiefly by a tax on Wall Street speculation, and Clinton unveiled a "New College Compact," which proposed a plan that would reduce costs for students and allow them to graduate from college without taking on debt, paid for by closing tax loopholes for the wealthy.

Sanders' plan has attracted the attention of some progressives for its simplicity and its declaration of college as a right, while Clinton's more targeted proposal, which offers aid based on the financial profile of students, has earned praise from others as more pragmatic and fair.

Warren's own forays into reducing the cost of college have hewed closer to the "debt-free" language of Clinton's proposals, but it's evident at the moment that she has one priority: Convince the public that no matter how dissatisfied liberal voters may be with Clinton's more incremental approach, it shouldn't lead to indifference about the prospect of a Republican victory.